HIF1A and cancer: Moreover, in tumor patients, HIF-1α expression has been observed to correlate with vascular endothelial growth factor (VEGF) over-expression, along with tumor stage and vascularization, lymphatic invasion, and metastasis, as shown in many cancer types such as esophageal squamous cell cancer, as well as colorectal and hepatocellular carcinomas [56,57,58,59].